At present, in a liquid crystal display (LCD), liquid crystal molecules in a liquid crystal layer deflect usually under the control of an electric field formed between a pixel electrode and a common electrode, to form a liquid crystal display. In particular, pixel electrodes within each pixel are charged through coordination of a transistor, a scan line and a data line so as to reach a given gray scale voltage, while the common electrode functions as a voltage common terminal to load a uniform common voltage. However, due to manufacturing process and so on, difference may exist in actual charging effects between different pixel electrodes, thereby resulting in poor display such as flicker or luminance mura. In this regard, although difference in the charging effects between different pixel electrodes can be compensated theoretically by adjusting a voltage of another terminal of the liquid crystal capacitor, i.e., the voltage of the common electrode, the common electrode taken as a voltage common terminal would simultaneously influence displaying of a plurality of pixels, and the loaded voltage cannot be adjusted for each pixel.